Research and development for application of photosensitive compositions containing a base polymerization initiator (a base-generating agent) to photoresist materials, photocurable materials, and so on has been actively conducted in recent years. For example, a method utilizing the phenomenon that a compound having an epoxy group (hereinafter, occasionally abbreviated as “epoxy compounds”) cures through undergoing crosslinking reaction caused by the action of a base has been proposed in which a base is generated in a resin composition containing an epoxy compounds through irradiation with light (an active energy ray) and then the epoxy compounds is cured through heating (e.g., Non Patent Literature 1).
For the curing of an epoxy compounds, a strong base such as a tertiary amine, an amidine, and a guanidine is used as a base polymerization initiator (a base-generating agent) which readily functions as a catalyst. Known examples of base polymerization initiators (base-generating agents) to generate such a strong base include aminimide base-generating agents (e.g., Patent Literature 1) which generates a tertiary amine, an amidine such as 1,5-diazabicyclo[4.3.0]-5-nonene (DBN) and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), an imidazole, or a pyridine, etc., through irradiation with light (an active energy ray), ammonium borate base-generating agents (e.g., Patent Literature 2, Patent Literature 3, Non Patent Literature 2, Non Patent Literature 3, Non Patent Literature 4, Non Patent Literature 5), and carbamate base-generating agents (e.g., Patent Literature 4). In addition, known are, for example, a base-generating agent which consists of a carboxylic acid and an amine and undergoes decarboxylation through irradiation with light (an active energy ray) (e.g., Patent Literature 5), a benzoic acid-based base-generating agent which undergoes cyclic esterification through irradiation with light (an active energy ray) (e.g., Patent Literature 6), and a tetraphenylborate base-generating agent which generates a guanidine such as 1,1,3,3-tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) through irradiation with light (an active energy ray) (e.g., Non Patent Literature 6). In addition, known examples of base polymerization initiators (base-generating agents) to generate a strong base other than tertiary amines, amidines, and guanidines include a tetraarylborate base-generating agent which generates a proazaphosphatrane such as 2,8,9-triisopropyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane through irradiation with light (an active energy ray) (e.g., Non Patent Literature 7). In addition, biguanides, which have higher basicity than amidines and guanidines, are known (e.g., Patent Literature 7, Non Patent Literature 8, Non Patent Literature 9), and an example in which a biguanide is used for curing an epoxy compounds (e.g., Patent Literature 8) and an example in which a compound obtained by salt formation of a pyrolytic compound and a biguanide is applied as a heat-curing catalyst (e.g., Patent Literature 9, Patent Literature 10) are known. In addition, the present inventors have reported a base-generating agent consisting of a carboxylic acid with a particular structure and a biguanide (Patent Literature 11).
Moreover, the present inventors have just recently reported a base-generating agent consisting of a borate with a particular structure and a strong base such as a biguanide (e.g., Patent Literature 12). The base-generating agent described in Patent Literature 12 has an anionic portion of a borate, by virtue of which the base-generating agent is characterized in that even after the base-generating agent is stored in a state in which the base-generating agent is mixed in a base-curable resin raw material such as an epoxy compounds for a long period, the base-generating agent does not cause curing of the base-curable resin raw material.